Flow spreader for papermaking machine



Feb. 8, 1966 P. H. GOLDSMITH 3,234,078

FLOW SPREADER FOR PAPERMAKING MACHINE Filed Nov. 19, 1962 3 Sheets-Sheet 1 INVENTOR Philip H. GOLDSMITH ATTORNEY Feb. 8, 1966 P. H. GOLDSMITH FLOW SPREADER FOR PAPERMAKING MACHINE 3 Sheets-Sheet 2 Filed Nov. 19, 1962 INVENTOR Philip H. GOLDSMITH ATTORNEY Feb. 8, 1966 P. H. GOLDSMITH FLOW SPREADER FOR PAPERMAKING MACHINE 3 Sheets-Sheet 5 Filed NOV. 19, 1962 lNI/ENToR Philip H. GOLDSMITH AT ORNEY United States Patent O 3,234,678 FLOW SPREADER FOR PAPERMAKING MACHNE Philip H. Goldsmith, 2255 Closse St., Montreal, Quebec,

Canada; Stuart Goldsmith, residuary legatee of said Philip H. Goldsmith, deceased Filed Nov. 19, 1962, Ser. No. 233,688 2 Claims. (Cl. 162-336) This application is a con-tinuation-in-part of application Serial No. 856,457, led December l, 1959, now abancloned.

This invention relates to flow spreader conduits for paper making machines and has as a main object to provide a spreader which Will receive the flow from the usual stock supply pipe and spread it smoothly at uniform velocity across the width of the machine to be supplied.

More specifically, the present invention aims to provide an improvement over the type of flow spreader described in the applicants United States Patent No. 2,465,445, issued March 29, 1949.

As described in this earlier patent, a flow spreader may comprise a single pass which continuously increases symmetrically in width and decreases in depth from its input to its output end, the cross-sectional area of the spreader at its output end being no greater than the crosssectional area at its input end. In order to increase the squeezing action, whereby the flow is more positively spread throughout the rwidth of the spreader, the cross-sectional area of the spreader conduit may continuously decrease somewhat from its input to its output with consequently increased flow velocity. In other words, the ratio of the cross-sectional area of the inlet end of the spreader may be to the cross-sectional area of its outlet end as one to one, or as one to one minus.

The possible length of a single pass spreader is limited by the space available, and this space is small in the case, for example, of a multi-unit cylinder machine where the spreaders are-arranged beneath their associated vats. In such case, the spreader must widen abruptly. Better re- -sults are secured where there is a more gradual widening throughout a greater spreading length and in accordance with the earlier invention this greater length is secured in a small space by providing a multiple pass spreader of serpentine or undulatory form with up-passes and down-passes arranged closely together. In this case, as described in United States Patent No. 2,465,445, each of the passes may be of substantially constant cross-sectional area throughout, or the cross-sectional area of each may be continuously decreased some-what throughout, the turnarounds at the upper and lower ends of the passes being in one design conveniently of constant width and depth. Even 'with this arrangement it may be difficult to hold outflow velocity suitably low without the use of an oversize stock inlet connection pipe. This latter difficulty is completely avoided, in accordance with the invention of United States Patent No. 2,465,445, by the use of turnarounds which enlarge in cross-sectional area in the direction of flow. Using such turn-arounds, each pass can easily have a requisite squeezing action for its spread and the output velocity can be any desired figure.

While the arrangement described in the applicants United States Patent No. 2,465,445 was a distinct improvement in the art over the existing flow spreaders, it was found .that flow spreaders, with the enlarged area of turn-around, gave evidence of insuflicient turbulence against the inside radius, and therefore had a tendency of accumulating slime at the beginning of a succeeding ass. p To correct this, in accordance with the present invention, it is proposed to create a turbulence zone at the beginning of each pass by shaping the spreader ow con- 3234,78 Patented Feb. 8, i966 ICC fining walls so that a sudden change of direction is irnparted to the flow whereby additional swirls or turbulences occur at each change of direction so that the interior passage is completely filled eliminating slime accumulating areas.

In the case of a single pass spreader, this is accomplished by making the wall facing the inlet as a substantially fiat surface disposed at substantially right angles to the 4incoming flow making the pass fully effective throughout its length.

In the case of multiple pass arrangements, it is proposed that in addition to the turbulence zone created in the rst pass that further similar zones are created at each turn-around by reducing the depth of the pass at the point of deflection at each turn-around to substantially less than the depth at the end of the preceding pass. Accordingly, the shape of each turn-around is no longer rounded in the direction of flow but is shaped to produce turbulence and to localize this turbulence in the turnaround passes. In this way, each succeeding pass becornes effective throughout substantially its entire length eliminating the slime accumulating tendencies mentioned above.

Having thus generally described the nature of the invention, particular reference will be made to the accompanying drawings showing by way of illustration a preferred embodiment thereof, and in which:

FIGURE 1 is an elevation of a cylinder machine installation with stock feeding means including a spreader having multiple passes with turn-arounds wherein at each end or direction diverting baffle the depth of the pass is reduced relative to the depth at the end of the preceding pa-ss, thus producing a localized turbulence.

FIGURE 2 is an enlarged side elevation of the spreader utilized in the construction of FIGURE 1.

FIGURE 3 is an enlarged end elevation of the spreader of FIGURE 2.

FIGURE 4 is an enlarged side elevation of a single pass dow spreader suitable for embodiment with construction showvn in FIGURE 1.

FIGURE 5 is an enlarged sectional view of the lower end of the construction shown in FIGURE 4 to illustrate the turbulizing action of the substantially fiat back wall abruptly changing direction of flow from the inlet.

In FIGURE l, reference numeral 11 designates a cylinder machine including a vat 12 and a cylinder 13, the latter being driven by a motor 14. Reference numeral 15 designates generally a spreader in accordance with the invention disposed below the machine 11 and in connection with the vat inlet opening by means of a conduit section lr6. Reference numeral 17 designates a white water conduit in connection with the vat and leading to a mixer 18 to which is also led the circulating stock outlet 19 from the vat and an input pipe 20 for new stock. The mixture is forced by a pump, not shown, into the lower end of a head box comprising an upwardly opened conical tank 21 concentrically disposed within an upwardly open conical tank 22. The mixture pumped into the tank 21 flows evenly over the top darn 24 with air removal, into the annular space between the two tanks. The stock flows from the bottom of tank 22 through a pipe 26, which is inclined somewhat upwardly in the direction of flow, to a downpipe 27 in connection with a fitting 28 which, as shown in FIGURE 2, is made as an integral part of the construction of the first pass 3l and has a circular section extending to and abutting a back plate 34.

The lower end of the side walls of the first pass 31 is conformed to match the contours of the fitting 28 at each side with the front plate 35 intersecting and meeting the upper contour of the fitting. Accordingly, and as will be described in more detail later, the input or inlet end 29 of the fitting is circular and the formation of the section of the first pass 31 at the point of intersectionwith'thefitting28 will be rectangular. This, of course, would also apply to the inlet end 129 and the formation of the` section of the single pass construction 131,'as `shown in FIGURES 4 and 5. The substantially right-angledinterf.

section of the iitting 128 with the beginning of the single pass 131` produces a sudden change of direction to the flow, as shown somewhat diagrammatically in FIGURE 5 creating a zone yof smallturbulences `and thus breaks v down the flow so that it lls the entire passage making in the rst pass 31 of the multipass spreader as will be i described.

Dealing now with the multi-pass construction shown,

and by way of illustration, it will be assumed that the feedconduit 26,27 is of 24 inch nominal diameter and that the machine 11 has a vat width of 140 inches.

A The inlet opening 29` of Viitting 28 has a diameter of- 235/5 and the rectangular pass section or outlet 30,'

located along a line parallel with the top of the fitting 28, has a width of 23%" and a depth of '181/2". This gives an input area of 438 sq. in. and a substantially equal output area, i.e. 437 sq. in. at the inlet `opening or start of the first pass.

As previously mentioned, it will be noted that thesubstantially right-angled interconnection of the fitting 28 ywiththe vfirst pass 31 produces a turbulizing effect to the flow of stock delivered to the rst'pass and thus eliminates possible cavitation at this point making the first pass fully effective throughout its length.

vThe `lirst pass 31 'of the spreader is disposed vertically on tting 28 and is 5 7" in height and has a' rectangular horizontal outlet opening which is 54 in width and 7 in depth and is symmetrically disposed with respect to the inletopening, i.e. the side Walls of the pass diverge at equal-angles from the vertical. area of the pass is reduced at the rate of 21/2 per running foot or for a total of about 14%. The area of theoutlet opening is.378 sq. in. whichis a reduction of 59 sq. in. If two rectangles of different size in parallel planes-are connected by straight lines joining their corners, then the rectangles of intermediate parallel planes will not bear a relation to the area of the end rectangles proportional to their distances from them in accordance with the present requirements. For example, the mid-area, or

area of the rectangle parallel to and equidistant from the other two planes, Will not be equal to the average of the other two areas, but much. greater. Therefore, if thel pass 31 were defined by four straight plates, the area between the inletand outlet Wouldactually be considerably The cross-sectional f greater through most of the length of the pass than :the f area at the inlet. There would not be a constant rate of change in area and squeezing action for every foot of the, spreading length. The pass 31, with the input. andl output dimensions above given, would have an intermediate area of 497 sq. in., an error of about 21%. In order to avoid this discrepancy and this should bedone for the best results, the side plates 32 and 33 down to the connection with the iitting 28 and the back plate 34`of pass 31 may be flat, the front platev 35 ybeing shaped as particularly shown in FIGURE 2 sothat the cross-sectional area of the passage is reduced ata constant rate. The frontzplate 35 is inwardly bowed giving a depth at one foot intervals, moving up, of 14.7",'12", 10:1,"8.7`

and 7.5".

vReference numeral 36 designates a turn-around having an inverted U-shaped passage 37( One leg of the turnaround is secured to the upper end of pass 31 and has an f `opening of the same dimensions as the outlet opening of the latter. Ashere shown, the passage 37 `has a constant widthbut enlarges in depth to a rectangular outlet opening whose dept-h is 12.31 with an area of 665 sq. in. The` turn-around has a mean flow length of 2"l%s. The output leg of the turnraround Seis secured to thetop of a pass 38 having a passage detinecl` by straight'side platesV 39`and .40 and a straight back plate 41, the: front plate 42 1being-bowed inwardly to obtain the constant-eifectabove mentioned.

In accordance ,with'the present invention,.the top orbale'V portion 35a of the turn-aroundV is made asbeing substantially -atrrather th-ana rounded section as shown in the applicants earlier United States Patent 2,455,445.v

This change in formation reduces thedepth of the passage -37 at the pointl A to substantially less than the depth of thek pass 31 at the upper` end. .'Eor example, as

noted above, vit the depth'of'the outlet end of thev pass 31wis"7 the depth of thefpassage; 37 is approximately 31/2" at point A'while the width remains constant.

This creates a turbulence. chamber. or zone Bjprod1 1cing a localizedscouring4 action eliminatmg lthe possibilities.

of slime accumulation :at they beginning of the succeeding pass 38.*` lFurther, this localized turbulence at the turnaround by eliminating -possible cavitation extends the ef.v

fective length of the succeeding spreader pass 38. 1

Pass 38 has an upper or inlet opening of the same dimensions as the outlet opening 1of theturn-,aronnd yand has a bottom rectangular opening which is 93" in vwidth and 5.75.'.l inidepth, providing an outlet'opening of 535 sq. in.r This is a reduction of sq. in., ,or about 19%,-

from the inlet. .This pass is 7'7" in length and, moving downwardly at one foot intervals, its depth is 10.9", 9.8, 8.85, 8", 7.25", 6.612" and 56.05";

Reference numeral 43 .designates a 4bottom turn-around having a U-shaped passage `44` with an inletcommuncating with and having thea-ame dimensionsas the outlet of passr 38.= Turn-around 43 is of constant Width but increases in depth to an outlet opening whose depth is 10.25 with an area of 953 sq. in. Themean ilow length isk 1 10%.. Again, thebottom or bale'f portion 43a of the-turnaround is VVmade as being substantially flat so las `to reducey the depth of the passage 44 Iat pointC to substanatially less than the depth of the passi38. Forexample, as noted above, if the pass 38 h-as -a depth at the outlet opening of wayof an example, the depthlof the turn-around flow passage at mid-point is preferably. approximately half the depth of the outlet opening of the preceding path.

while the Width ofthe turn-around remains constant. This produces a localizedzone of turbulence within theV turnaround pass -making each succeeding pass effective.V

throughout substantially, its whole length.

As previously discussed, jthe construction of the tting 28 and the connectionto the inlet end ofthe tirst pass 31 Ialso produces a zone ,of` turbulenceat this point making; the lirst pass effective throughout scubstantially its entirev length.

"Reference numeral-4S designates a pass having an inlet opening of-the same dimensions as the outlet end of turnaroundQ43 and incornmunication therewith. The pass is defined by straight side plates 46 and .47 and a straight back plate -48,1the front plate 49 being bowed inwardly and the arrangement being such'as to provide an outlet opening havingga width `of 140. andqa depth of 5%",y

givingV an .area of 735 sq. in. ,The reduction in the area is217 sq. in.y or about 22.7%.v Thepass45 is 91 high and, moving Yup `at one foot intervals, the shapeV of the` front plate 49 is such. that the depths are as follows: 9.45", 8.75", 8.1"', 7.5", 7", 6.5, 5.61 and 5.28".

The top ofthe pass 4SV is connected directly with the,.-

vfeed opening 70 of -the vat 12 .as shown in FIGUR-E 1.

It has beeniassumed inthe Vabove description that the. vat Width isf", but the Vat Width Vcould bey anywhere from that `figure down to 93". In the latter ease, keeping the same depth at the outlet end of the iinal pass, the outlet area would be 488 sq. in., a decrease in area of 465 sq. in. With a 140 spreader and a velocity of 5.9 fps. at fitting 2S the velocity will rise to 6.8 at the top of the first pass, drop to 3.9 in the top turn-around, rise to 4.8 in the second or down-pass, drop to 2.7 in the bottom turn-around, and rise in the final pass to 3,5 at 8,000 gpm. In the 93 spreader, with an input velocity of 3.9 taps., the velocity will rise to 4.5 in the lirst pass, drop to 2.6 in the top turn-around, rise to 3.2 in the down-pass, drop to 1.8 in the bottom turn-around, and rise to 3.5 at the top of the tinal. up-pass at an output of 5,300 gpm.

The over-all length of the illustrated .multi-pass spreader, with fitting 28, is less than 6 feet so that it is readily disposable beneath an associated vat which will have, for example, a length in the neighbourhood of 9 feet.

Using a rated l inlet itting, the final spread can be from 79 to 120" in width with a depth of 4.25; with a diameter inlet tting the outlet opening can have a width of from 119 to 180 with a depth of 61/z; and with a 38 diameter inlet fitting the outlet opening can be from 157" to 240" in width with a depth of 7%. Thus with the four sizes of inlets i.e. 20, 24, 30" and 38, the spread can range anywhere from 79" to 240".

Fitting Z8 is provided with bottom clean-out doors 50 at each side, see FIGURE 3. The up-pass 31 has Wash-out doors 52 and 53 near its upper end and the turn-around 36 has Wash-out doors 54 and 55. The top wall of the turn-around is provided with an outlet nipple 57. A pipe 58 connects nipple 57 with the white water pipe 17. A pipe 62 connects the highest part of the inclined stock feed pipe 26 with white water pipe 17, thus preventing the formation of air locks and air venting to the feed system in advance of the air release means constituted by the up-riow head box. The venting system must always be on the rise or at least must not dip below horizontal since otherwise an air lock will forni in it.

In FIGURE 3 it will be seen that the down-pass 38 and the final up-pass 45 are provided near their upper ends with wash-out doors and that the bottom turn-around 43 is provided at one side with a wash-out door 65 and at the other with a dump valve 66.

In FIGURES 1, 2 and 3, three spreading passes are shown but any appropriate number from two on up may be used. With reference to FIGURE 4, a single pass spreader, in accordance with the invention, can be varied in length to suit requirements with the top 145 of the pass being adapted for connection directly to the feed opening ot the vat 12, as shown in FXGURE l.

I claim:

1. In a flow spreader conduit for a paper making machine, said conduit having an inlet opening for connection to a stock supply pipe, said conduit having an outlet opening Whose width is substantially that of the machine, said conduit being of undulatory form and comprising at least two generally upright serially connected passes each having an inlet and outlet end, and a turn-around connecting adjacent ends, the outlet end of one with the inlet end of the following of said passes, each of said passes progressively increasing in Width and decreasing in depth in the direction of flow, the cross-sectional area of the outlet end of each pass being no greater than that of its inlet end, said turnaround having a reduction in depth intermediate said input and output end to substantially less than the depth at the end of the preceding pass; the improvement wherein said turn-around has a dat outer dow coniining wall at right angles to the mean direction of ow in said passes spanning said passes and the point of said reduction in depth whereby a localized turbulence is created within said turn-around larger area output end.

2. A flow spreader as claimed in claim 1, wherein the depth of turn-around at said point of reduction is sub stantially half the depth of the outlet end of an upright pass and the Width of said turn-around remains constant between said inlet and outlet ends.

References Cited by the Examiner UNITED STATES PATENTS 809,073 1/ 1906 McNaught 162-337 1,821,198 9/1931 Zimmerman 162-343 2,205,693 6/1940 Milne 162-343 2,465,445 3/ 1949 Goldsmith 162-336 2,65 8,429 11/1953 Malkin 162-343 OTHER REFERENCES Bratton et al.: The Flow Spreader, The Paper Industry and Paper World, pp. 1062, 1064, and 1066, January 1943.

Van der Meer: Hydraulics of Flowbox and Slice, Tappi, pp. 502-511, November 1954.

DONALL H. SYLVESTER, Primary Examiner.

MORRIS O. WOLK, Examiner. 

1. IN A FLOW SPREADER CONDUIT FOR A PAPER MAKING MACHINE, SAID CONDUIT HAVING AN INLET OPENING FOR CONNECTION TO A STOCK SUPPLY PIPE, SAID CONDUIT HAVING AN OUTLET OPENING WHOSE WIDTH IS SUBSTANTIALLY THAT OF THE MACHINE, SAID CONDUIT BEING OF UNDULATORY FORM AND COMPRISING AT LEAST TWO GENERALLY UPRIGHT SERIALLY CONNECTED PASSES EACH HAVING AN INLET AND OUTLET END, AND A TURN-AROUND CONNECTING ADJACENT ENDS, THE OUTLET END OF ONE WITH THE INLET END OF THE FOLLOWING OF SAID PASSES, EACH OF SAID PASSES PROGRESSIVELY INCREASING IN WIDTH AND DECREASING IN DEPTH IN THE DIRECTION OF FLOW, THE CROSS-SECTIONAL AREA OF THE OUTLET END OF EACH PASS BEING NO GREATER THAN THAT OF ITS INLET END, SAID TURN-AROUND HAVING A REDUCTION IN DEPTH INTERMEDIATE SAID IMPUT AND OUTPUT END TO SUBSTANTIALLY LESS THAN THE DEPTH AT THE END OF THE PRECEDING PASS; THE IMPROVEMENT WHEREIN SAID TURN-AROUND HAS A FLAT OUTER FLOW CONFINING WALL AT RIGHT ANGLES TO THE MEAN DIRECTION OF FLOW IN SAID PASSES SPANNING SAID PASSES AND THE POINT OF SAID REDUCTION IN DEPTH WHEREBY A LOCALIZED TURBULENCE IS CREATED WITHIN SAID TURN-AROUND LARGER AREA OUTPUT END. 